"'A deal is on the table and it can be done. But it is a formidably difficult negotiation, I can't say exactly when it will conclude,' he said.

"Asked why the negotiations had apparently stalled, Mr Hague said there were 'still some gaps' between Iran and other leading members of the international community, including the US, UK and Russia.

"He said: 'They are narrow gaps. You asked what went wrong, I would say that a great deal went right.'"

During three days of talks in Geneva, the sides were trying to hammer out a deal to freeze Iran's nuclear program for six months, while seeking a longer-term deal. Iran was asking for an easing of U.S. sanctions. The U.S. and France seemed at odds over just what a freeze would mean for Tehran.

The bigger issue here is that the West has maintained that Iran is racing to make a nuclear weapon, while Iran insists its nuclear program is for peaceful purposes only.

Working into the early hours of Sunday, negotiators called it quits. The New York Times reports that the European Union's foreign policy chief, Catherine Ashton, and Iran's foreign minister, Mohammad Javad Zarif, emerged together to break the news.

"A lot of concrete progress has been made, but some differences remain," Ashton said." I think it was natural that when we started dealing with the details, there would be differences."

What's interesting about the negotiations, the paper points out, is that it wasn't differences between the P5+1 (Britain, China, France, Russia, U.S., plus Germany) and Iran that doomed a deal, instead, it was a rift among the negotiating group of world powers that scuttled a deal.

This meeting had set up high hopes for a historic breakthrough, especially because Secretary of State John Kerry cut a trip to the Middle East short to join the talks.

All sides said they would meet again. But if you want to read tea leaves, here's a telling sign: The sides will return to the table, but this time it won't bring together the foreign ministers of the world powers. The negotiations will be held at the political director level.